Magnetic resonance imaging of the tensor vastus intermedius: A topographic study based on anatomical dissections.

The tensor of the vastus intermedius (TVI) is a newly described component of the extensor apparatus of the knee joint. The objective of this study was to evaluate the appearance of the TVI on magnetic resonance (MR) imaging and its association with the adjacent vastus lateralis (VL) and vastus intermedius (VI) muscles and to compare these findings with the corresponding anatomy. MR images were analyzed from a cadaveric thigh where the TVI, as part of the extensor apparatus of the knee joint, had been dissected. The course of the TVI in relation to the adjacent VL and VI was studied. The anatomic dissection and MR imaging revealed a multilayered organization of the lateral extensor apparatus of the knee joint. The TVI is an intervening muscle between the VL and VI that combined into a broad flat aponeurosis in the midthigh and merged into the quadriceps tendon. Dorsally, the muscle fibers of the TVI joined those of the VL and VI and blended into the attachment at the lateral lip of the linea aspera. In this area, distinguishing between these three muscles was not possible macroscopically or virtually by MR imaging. In the dorsal aspect, the onion-like muscle layers of the VL, TVI, and VI fuse to a hardly separable muscle mass indicating that these muscles work in conjunction to produce knee extension torque when knee joint action is performed. Clin. Anat. 30:1096-1102, 2017. © 2017 Wiley Periodicals, Inc.

Intravascular lymphoma mimicking cerebral stroke: report of two cases.

Ischemic stroke is a serious disease leading to significant morbidity and mortality. Multifocal and recurrent strokes are usually caused by embolic diseases, i.e. atrial fibrillation, but rare causes like cerebral vasculitis and clotting disorders are also well known. Here we report on two patients suffering from the very rare intravascular large B-cell lymphoma leading to multifocal and recurrent strokes in the brain and spinal cord as the prominent neurological symptom. The difficulties and the need for diagnostic brain biopsy in making an 'in vivo' diagnosis in this particular disease are outlined. Furthermore, the prerequisite for an interdisciplinary approach in these patients is strongly emphasized. Delayed diagnosis for several reasons was the most probable cause for cerebral relapse leading to death in one patient a few months after diagnosis. Conversely, early initiation of immunochemotherapy with a classical lymphoma schedule (R-CHOP) led to long-lasting remission of the disease in the other patient. With this report we like to improve alertness to intravascular large B-cell lymphoma as a cause for multifocal and recurrent strokes.

Safety and reliability of Radio Frequency Identification Devices in Magnetic Resonance Imaging and Computed Tomography.

BACKGROUND: Radio Frequency Identification (RFID) devices are becoming more and more essential for patient safety in hospitals. The purpose of this study was to determine patient safety, data reliability and signal loss wearing on skin RFID devices during magnetic resonance imaging (MRI) and computed tomography (CT) scanning. METHODS: Sixty RFID tags of the type I-Code SLI, 13.56 MHz, ISO 18000-3.1 were tested: Thirty type 1, an RFID tag with a 76 x 45 mm aluminum-etched antenna and 30 type 2, a tag with a 31 x 14 mm copper-etched antenna. The signal loss, material movement and heat tests were performed in a 1.5 T and a 3 T MR system. For data integrity, the tags were tested additionally during CT scanning. Standardized function tests were performed with all transponders before and after all imaging studies. RESULTS: There was no memory loss or data alteration in the RFID tags after MRI and CT scanning. Concerning heating (a maximum of 3.6 degrees C) and device movement (below 1 N/kg) no relevant influence was found. Concerning signal loss (artifacts 2 - 4 mm), interpretability of MR images was impaired when superficial structures such as skin, subcutaneous tissues or tendons were assessed. CONCLUSIONS: Patients wearing RFID wristbands are safe in 1.5 T and 3 T MR scanners using normal operation mode for RF-field. The findings are specific to the RFID tags that underwent testing.

Analysis of lesions in patients with unilateral tactile agnosia using cytoarchitectonic probabilistic maps.

We propose a novel methodical approach to lesion analyses involving high-resolution MR images in combination with probabilistic cytoarchitectonic maps. 3D-MR images of the whole brain and the manually segmented lesion mask are spatially normalized to the reference brain of a stereotaxic probabilistic cytoarchitectonic atlas using a multiscale registration algorithm based on an elastic model. The procedure is demonstrated in three patients suffering from aperceptive tactile agnosia of the right hand due to chronic infarction of the left parietal cortex. Patient 1 presents a lesion in areas of the postcentral sulcus, Patient 3 in areas of the superior parietal lobule and adjacent intraparietal sulcus, and Patient 2 lesions in both regions. On the basis of neurobehavioral data, we conjectured degradation of sequential elementary sensory information processing within the postcentral gyrus, impeding texture recognition in Patients 1 and 2, and disturbed kinaesthetic information processing in the posterior parietal lobe, causing degraded shape recognition in the patients 2 and 3. The involvement of Brodmann areas 4a, 4p, 3a, 3b, 1, 2, and areas IP1 and IP2 of the intraparietal sulcus was assessed in terms of the voxel overlap between the spatially transformed lesion masks and the 50%-isocontours of the cytoarchitectonic maps. The disruption of the critical cytoarchitectonic areas and the impaired subfunctions, texture and shape recognition, relate as conjectured above. We conclude that the proposed method represents a promising approach to hypothesis-driven lesion analyses, yielding lesion-function correlates based on a cytoarchitectonic model. Finally, the lesion-function correlates are validated by functional imaging reference data.

Extraneural spread of glioblastoma--report of two cases.

BACKGROUND: Glioblastoma, a highly aggressive tumor, accounts for the majority of all primary brain tumors in adults. Despite a destructive local growth pattern, extraneural spread of these tumors is extremely rare. CASE 1: We describe the case of a 58-year-old man with glioblastoma, in whom an epidural mass was diagnosed 5 months after initial local therapy of the brain. A positron emission tomography (PET) scan revealed multiple metastases in the lungs, in the retroperitoneum, and in the left trochanter minor region. A soft tissue swelling of the right thigh was histologically proven to be metastatic tissue from the primary glioblastoma. The patient died 11 months after initial diagnosis. CASE 2: A 47-year-old woman with recurrent glioblastoma had a long lasting complete response to chemotherapy. 2 years after initial diagnosis she presented with a pleural mass which was a metastasis of the formerly diagnosed glioblastoma. CONCLUSION: Although systemic metastases in glioblastoma are rare, different organs can be involved.

Pseudotumor of gout in the patella of a kidney transplant recipient.

BACKGROUND: A 33-year-old renal transplant recipient presented with painless swelling of the right knee. Physical examination revealed an impressive knee joint effusion with no signs of inflammation. The patient did not remember a recent trauma, but he mentioned a strain 3 years earlier; radiographic findings had been normal at that time. The patient had suffered from end-stage renal disease due to chronic glomerulonephritis and had previously undergone two transplantations. At presentation, his kidney function was stable under treatment with ciclosporin, azathioprine and steroids. INVESTIGATIONS: Conventional radiography revealed a tumor at the superolateral pole of the right patella. Extensive soft tissue invasion and bone destruction was seen on MRI. A knee arthroscopy with biopsy, performed to aid diagnosis, showed extensive chondrocalcinosis macroscopically; histologically, gouty tophi were found. DIAGNOSIS: Pseudotumor of gout in the patella. MANAGEMENT: Uric-acid-lowering therapy with benzbromarone was started immediately after diagnosis. A local arthroscopic debridement of the right knee joint was performed 4 months later, and the patient remained asymptomatic for the next 3 years.